Expression of yeast cyclophilin A (Cpr1) provides improved stress tolerance in Escherichia coli.

Cyclophilins contain the conserved activity of cis-trans peptidyl-prolyl isomerase that is implicated in protein folding and function as molecular chaperones. The yeast cyclophilin A gene (cpr1) was subcloned to the prokaryotic expression vector pKM260. It was found that the expression of Cpr1 drastically increased the cell viability of E. coli BL21 in the presence of abiotic stress conditions, such as cadmium, copper, hydrogen peroxide, heat, and SDS. Thus, this study illustrates the importance of Cpr1 as a molecular chaperone that improved cellular stress responses when E. coli cells were exposed to adverse conditions, and it also shows the possibility of increasing the stability of E. coli strains utilized for the production of recombinant proteins.

A cyclophilin A CPR1 overexpression enhances stress acquisition in Saccharomyces cerevisiae.

Cyclophilins are conserved cis-trans peptidyl-prolyl isomerase that are implicated in protein folding and function as molecular chaperones. We found the expression of cyclophilin A, Cpr1, changes in response to exposure to yeast Saccharomyces cerevisiae to abiotic stress conditions. The effect of Cpr1 overexpression in stress responses was therefore examined. The CPR1 gene was cloned to the yeast expression vector pVTU260 under regulation of an endogenous alcohol dehydrogenase (ADH) promoter. The overexpression of Cpr1 drastically increased cell viability of yeast in the presence of stress inducers, such as cadmium, cobalt, copper, hydrogen peroxide, tert-butyl hydroperoxide (t-BOOH), and sodium dodecyl sulfate (SDS). The Cpr1 expression also enhanced the cell rescue program resulting in a variety of antioxidant enzymes including thioredoxin system (particularly, thioredoxin peroxidase), metabolic enzymes (glucose-6-phosphate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase), and molecular chaperones (Hsp104, Hsp90, Hsp60 and Hsp42). Thus, our study illustrates the importance of Cpr1 as a molecular chaperone that improves cellular stress responses through collaborative relationships with other proteins when yeast cells are exposed to adverse conditions, and it also premises the improvement of yeast strains.